Oil pressure warning light 2005 Jeep Liberty

amerbeauty97

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Hi! Me again with the 2005 Jeep Liberty; just about 89k in mileage. So I had a high mileage oil change done on the 24th. Today after driving approximately 50-60 miles, my oil pressure warning light started to go on and off but luckily no noise or difference in driving. Noticed it went off when the RPM was over 2. Took it back to have the components of the oil changed checked (as close to where I was as possible; 3.2 miles) and they said everything is correct and that oil levels are good. Said it was probably a sensor but they don’t do it there. Drove home (30 miles) and still had it intermittently going on and off but more frequently even at 65 mph and stayed on longer. Went straight to the mechanic but he can’t do anything until Tuesday due to the holiday. Oil level was still good and still no noise under the hood. What’s my best course of action to make it to Tuesday? Thanks for any help or advice.
 

tommudd

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Just the oil pressure switch mounted right above the oil filter , they go bad
have a MOPAR one installed ( only )
If oil is correct level, go.....
 

amerbeauty97

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Just the oil pressure switch mounted right above the oil filter , they go bad
have a MOPAR one installed ( only )
If oil is correct level, go.....
Thanks! I read through the others but saw that they had compounding events that happened like stalling or noise so I was questioning myself. I definitely will have them use only mopar. Is there a reliable place where I can see part costs so I can estimate what I’m looking at financially? Thankfully, I’m not going on any long term expeditions but I just wanted to check that if I have to go to the store, I have a good chance of being ok so long as I check the oil level.
 

DadOSix

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The sensors get gummed up from time to time. Can take it out and clean it up, but if going that far, just as well to replace.
 

Grumpacus

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Mine was doing the same thing, figured the sensor was bad, turned out it just needed to be pushed in all the way.
 

duderz7

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The socket is nice, but not necessary. I went ahead and bought the socket mostly because I was replacing the sender on my Yukon about the same time. That one is a blind drop between the firewall and intake manifold while sitting on the battery. It's nice having a socket that holds the sensor on the way down.
 

sumosumo

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Hi! Me again with the 2005 Jeep Liberty; just about 89k in mileage. So I had a high mileage oil change done on the 24th. Today after driving approximately 50-60 miles, my oil pressure warning light started to go on and off but luckily no noise or difference in driving. Noticed it went off when the RPM was over 2. Took it back to have the components of the oil changed checked (as close to where I was as possible; 3.2 miles) and they said everything is correct and that oil levels are good. Said it was probably a sensor but they don’t do it there. Drove home (30 miles) and still had it intermittently going on and off but more frequently even at 65 mph and stayed on longer. Went straight to the mechanic but he can’t do anything until Tuesday due to the holiday. Oil level was still good and still no noise under the hood. What’s my best course of action to make it to Tuesday? Thanks for any help or advice.
Just change the oil pressure sensor .i had the same issue with both my kids jeep lib 04 and 05 3.7l .its the sensor ,easy to change
 

jdom5274

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Don’t be so quick to indict the sending unit. These oil change locations are using 5w-30 oil and no longer use 10w. These KJ’s were engineered in the early 2k’s and don’t have the proper heat treated parts to use 5w oils. I strictly use 10w - 40 oils in my wife ‘04 and no longer does the oil light go off even near zero degrees F. Oil is always cheaper than wiping out an engine
 

Jar

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MOPAR parts fail because they go with the cheapest manufacturer with the best tolarences. Just change the oil pressure switch. This happened on my daughters 02 Liberty and my 02 Ram. Both replaced with box store parts. No problems for many years. MOPAR fails like any other(Chevy/Ford/Toyota/Nissan/Honda and so on); buisness is based on this practice. TRW is sold and labled as MOOG! So is moog a factory part sold at a lower price or MOPAR better. MOPAR is not your only choice, just do your home work!
 

dutch

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The socket is nice, but not necessary. I went ahead and bought the socket mostly because I was replacing the sender on my Yukon about the same time. That one is a blind drop between the firewall and intake manifold while sitting on the battery. It's nice having a socket that holds the sensor on the way down.
 

jdom5274

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Don’t be so quick to indict the sending unit. These oil change locations are using 5w-30 oil and no longer use 10w. These KJ’s were engineered in the early 2k’s and don’t have the proper heat treated parts to use 5w oils. I strictly use 10w - 40 oils in my wife ‘04 and no longer does the oil light go off even near zero degrees F. Oil is always cheaper than wiping out an engine
Update: last Friday (1/28/22) the oil light went off while coming up to a stop light. Outside temp About 24 deg F. After checking oil level when back home and finding it right on target I found my new sensor in my stock. Today (1/30/22) I changed the sensor after I installed a tee for a real gauge. At startup oil pressure near 75 lbs cold. After allowing to get to full temp at idle - 45 lbs. outside temp was 28 deg. I replaced sensor and capped the tee so I could check again in the future. The 10w-40 still in there. With all respect to our moderator, the higher milage over 75k needs to increase the viscosity over the factory recommendations. The lower weight oils are attempts to bump up the CAFE fuel averages at the expense of the motor. Oil is ALWAYS cheaper that motor replacement or overhaul.
 

tommudd

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With all respect to you I have one 03 KJ at 175,000 plus and one 04 KJ at 234,000 and both still run 5-30, both use hardly any ( less than 1/3 of a quart , between changes and only run Mobil ( and not the high mileage stuff either )
When I do OLF for any of my customers I use the same as well
I'll debate the use any time you want to Sir
Believe what you want , older cars from the 60 and 70 maybe yes, newer ones no

Using oil that is thicker than recommended may lead to a decrease in fuel economy, a higher load on your engine, and even a shorter life for your engine. Conversely, using thinner, lighter-weight oil than recommended can cause excessive wear and shorter life.
 

duderz7

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I would think the higher oil pressure on startup is a pretty good indicator of the engine under increased load, but what do I know? Just thinking logically. Tom, why not the high mileage stuff from mobil? What do you know?
 

Trainmaster

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Just did the job on a 2005 3.7. Here are some tips. Use the Mopar sensor. It's $40 and you'll only do the job once. It uses the same 1-1/16" socket as the one you're removing. A Chinese one will probably need a 26mm socket or something as well as the 27mm.

Save a lot of swearing and remove the oil filter and dump the mouthwash that's been in the motor for six months. Spray the oil and mung off the plug on the sender working from above. How do those power steering hoses look?

The plug has a red locking slide that keeps you from pressing in the retention tab to loose the socket. You can pull out the curved end of the red tab, working from below or push in the other end of the tab. Once you've moved the red tab, press on the retention tab while wiggling the plug. It should easily slip off. There's a YouTube video that shows how the locking tabs work. Be gentle. It's a single wire on this thing and you don't want to break it or pull it out of its plug.

You're working on the blind now so feel around with a loose 1-1/16" deep socket and wiggle it over the sensor. Get a short handle on it and it shouldn't be too tight.

The new Mopar sender switch threads in and has pipe dope already on it. Working from above feel around for the hole it threads into. Hand tight and then a few turns with the socket. Don't forget to replace an oil filter and oil.

If you're cheap and used a Chinese sender switch and two different sockets, don't bother locking the red tab. You'll be replacing the sender again in two months.

Hope this helps you guys. About an hour's job.
 
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Duster

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I don't usually do this but this time around, I'm going to second the use of Mobil 1 in these engines.

I've never worried too much about the viscosity numbers. The older ones called for 5w30 and the newer ones called for 5w20. The engine as far as I can tell did not change. So 0w20 5w20 0w30 5w30 10w30.

A previous Dodge engine a friend of mine had needed a quart of something thicker. It had an actual pressure gauge and it had a cold start clatter on winter mornings. This took care of the clatter and increased the oil pressure a little. So the first time I heard mine clatter on a cold morning start, I went and asked if I needed to do this with the 3.7L and in doing that, I have seen the oil passages on these years ago. I personally would not put anything thicker than __w30 in these engines, nor would I ever put cheap crap in it that might varnish or gum up worse. Just would not do it. I've seen what happens and it is not pretty.

I usually go with the intention of buying Mobil 1 5w30 but if it is sold out I just reach for one of the others. I assume the 5w20 is for fuel economy for the manufacturer where a 0.001 MPG increase matters. In my useage, I have never been able to tell an MPG difference. So I don't usually get the 5w20 or 0w20. It don't get all that cold here either.

Anyways, in my opinion this engine likes the Mobil 1 oil. I've ran the standard, the EP, the high mileage, the high mileage EP because again I usually shoot for the 5w30 and they usually have one of those in 5w30. Seems to like any of it fine.

I did however switch over to high mileage oil because I started leaking. I did not know at the time it was because I was having weird PCV valve issues. Prior to that I had never tried any of it. It of course did not slow the leaking because it was pressure pushing it out. After resolving the PCV issue it slowed the leaking to weeping. And it has kept on weeping. Right now it has the black bottle Valvoline Synthetic high mileage for over 150k in it because someone talked me into trying it saying that it would stop the weeping. I will be draining that out as soon as I get a chance because I can absolutely tell a difference. It just don't sound good. I don't know what it is, but I can detect a noise at idle sometimes that I have never heard before.

Anyways, Mobil 1 for the win for me. I try to buy it on sale and usually save most or all of the extra coin it costs. It's been working great for me for almost 240k in the Jeep. Over 330k in the truck before it. My Acura Turbo specs Mobil 1 5w30 only on the oil cap. The Mazda gets it too. Water outlet just broke on it like a month ago. No doubt in my mind the oil saved the engine. My mowers and ATV's also get their respective Mobil 1.

I am not some fanboy. It just works for me. It's saved my ATV racing engines several times when I had issues that should have fried them. I've torn those engines down and they look brand new inside still. I have one that should be rebuilt at minimum twice a season. I raced it 7 seasons, plus recreational riding hours. It still has the same compression it had when it was originally broken in. I probably should tear it down this winter and replace the crank, rod, piston, valves and springs, just for fear of metal fatigue... in other words to prevent a catastrophic failure like a broken crank, rod, piston, valve coming through the bottom, side, or top of the motor, just from fatigue, because at this point that is what I know is going to happen before it ever generates enough wear to loose an compression. And it is much cheaper to prevent than turn it into a basket case.
 
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